Going home to Wales is like going back to a friend and gives me a new lease of life. But Wales has always been an idea and tinged with pain, because the worst thing you can do is to leave home.

'Fear is a man's best friend' - it was the title of a song, and that's what I've learnt in New York - everyone walks with eyes in the backs of their heads in fear and loathing of each other, in healthy proportions.

Lou Reed and I were motivated by a perverse sense of jealousy between two people who wished they were the other person. I was jealous of his incredible facility with words, and he was jealous of my interest in sound. It was like two planets colliding. It was going to last so long, and there was no reason for it to last any longer.

With women, it's about finding somebody who lives at the same pace as you and is independent, who gets on with their work and lets you get on with yours. I think being on the same block - maybe even the same building - is good, but shared space is a very complex matter.

On 9/11 there was this floaty, ghostly kind of screaming going past my window. I live two blocks away; I was online at the time, when the sun went out. Normally, when you hear screaming you hear people running, and I thought, 'How come I'm not hearing any people running?' I got to the window and realised why: they were running on two inches of dust.

Nico was determined not to be a pagan view of a woman. Being a beauty icon in a magazine was not her idea of salvation.

The Velvet reunions happened because of guilt. There was so much shit left undone.

Ginsberg told me the only way to get friends in New York is to physically hang on to them and never let go. I'd been in New York about two months when he told me. My balloon completely burst.

Andy Warhol was the tightest motherfucker you'll ever meet, but always a generous friend to me.

Drugs were a competition with yourself, to see whether your body was in control of the drugs or the drugs in control of your body, or your mind in control of the drugs or the drugs in control of your mind - and you end up being split up. The thing that did it for me was that all this was affecting my sense of humour. Then my daughter was born and my sense of humour came back.

It's hard to get inside an artist's head, and as a producer you pull whatever tricks are necessary to get something out. You put a stone in someone's shoe and it'll force them to stop instead of walk.

I like to discern patterns in things. I read medical text books as many times as it takes, or anything, long enough until there's a pattern to see, until things fall into place.

I need to know who to ask about things. I used to go to the Arab Anti-Defamation League in Washington and learn about what it meant anthropologically to demolish someone's home. I have friends at the World Bank and the United Nations to ask about the food programmes, or science and technology, or Russia.

If I said I found the cult of the Velvet Underground distasteful, it must have been around then. I'm so far away from it all now it's as if the cult didn't exist, and that's a big release. This took a long time to happen, but now it's happened, I'm really enjoying it.

This is the most positive, successful period of my career. Admittedly, it's all over the place.

I'm bent on proving you can make a living as an artist and not die young and crazy like Mozart, Lenny Bruce, Dylan Thomas and so many others who risked their lives to make things they believed would be their salvation.

I wanted to go back to classical music because I thought that was the solution. Angst, that's what it was, a lot of angst. It seemed to be a plan. You go back to Dylan Thomas to see what got you interested in him back in Wales. Then you go back to classical music to see what it was back there that got me going.

Whatever you put in, you get back in spades. It comes down to listening to other people, and how much time you're prepared to allocate to another person. I've learnt most from my daughter.

The Velvet Underground did something to my sense of time. We were trying to get a lot done. But we didn't - our improvisations got longer and longer, each of us going out to follow the other, to the point that we weren't even a band any more.

I still have to look at the whole Velvet Underground period and balance it off. To see what was achieved since and before, and try to understand what happened with time. One of the things that you regret most is the amount of time that went into experimenting and asking: 'Did you prove or disprove the theorem in the end?' The theorem is: 'Are you really the person you think you are?' And the answer is 'Yes.'